Well we had a productive summer with the little boat , made some additions and had a little bit of progress . We are happy with the results so far and it does everything i wanted it to do but knowing there is more to be had as far as the top end just makes me want to keep tweaking it . Last summer we added a very nice manual lift mount to the boat with a two inch set back. We raised the motor about 2 inches and were able to get a couple more mph out of t before the dreaded porpoise reared its ugly head . There is more to be had lift wise but we stopped at two for now . To be sure we were not running too high for the water pickup I utilized a little trick I saw at a hydro race and re routed the water exhaust port into the boat and thru the hull to my immediate right . I can actually see the stream as well as feel the heat with my hand to monitor the engine temp manually as it were.
To describe our limit i can best say that just when i hit that last little bit of trim in the up button at about 38 mph you can literally feel the boat free up from the water and start to surge ahead . Unfortunately that is when the porpoising starts at about 40 mph. The feeling is that the boat starts to skip as the prop digs in , the bow raises , prop comes out of the water , nose comes down and then repeat . This is an exaggeration of the motions but that is what it feels like and i think you can see a bit of what i'm trying to explain in the videos i've added . All speeds are recorded via GPS and my rpm is 5100 . The sweet spot for my 1994 Johnson 50 is about 5400 btw.
No someone gave me a interesting thought which i wanted to run by you all and see what you thought. He surmised that with the rear of the boat being completely flat that the drag at the stern might be one of my problems and perhaps a experiment might be in order . We all are aware of boats that run " on the pad " such as a Hydro Stream or Allison . His ideas was that if perhaps we could build into the bottom a small angled pad that the boat could get up on and free up some of that drag. Nothing like a deep V but just a gradual angles pad under the boat . We haven't talked about size or anything but perhaps something 18 or 24 inched wide at the stern and extending forward 24 inches or so with a total thickness of an inch or two at the rear. Its just an idea and would not be too hard to fabricate or install .
In any event we are having a ball with the boat and could leave it alone and be very happy but hot rodders whether on land or sea just have to tweak to be happy . I've messed with my road toy for 18 years now and still can think of things I want to do .
As usual i appreciate any input and I will be more active checking in with what is going on with you all .
https://youtu.be/UftPvxYacuAhttps://youtu.be/eYH2mNHITbU